bpo-37913: Link to NotImplemented from new docs (GH-15860)
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 6b9325d..c6c6e40 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -2156,9 +2156,9 @@
Called to implement :func:`operator.length_hint`. Should return an estimated
length for the object (which may be greater or less than the actual length).
The length must be an integer ``>=`` 0. The return value may also be
- *NotImplemented*, which is treated the same as if the ``__length_hint__``
- method didn't exist at all. This method is purely an optimization and is
- never required for correctness.
+ :const:`NotImplemented`, which is treated the same as if the
+ ``__length_hint__`` method didn't exist at all. This method is purely an
+ optimization and is never required for correctness.
.. versionadded:: 3.4